Organotin compounds have hitherto been investigated widely, among which several or more compounds have been put to practical applications as stabilizers for organic compounds or as pesticides. Among organotin compounds, those having one or more tin-oxygen bonds such as R'.sub.3 SnOR", R'.sub.2 Sn(OR").sub.2, R'Sn(OR").sub.3 and Sn(OR").sub.4 wherein R' is an alkyl or aryl group and R" is a hydrogen atom or an alkyl or aryl group have been reported in a number of literature and patent specifications. For example, Amberger et al. reported that the reaction of (diethylamino)trimethylstannane (II) with methanol gives (methoxy)trimethylstannane (III) according to the following equation: ##STR3## [refer to Angew. Chem. Intern., Ed. Engl., 3, 138 (1964)].
Up to date, however, there exists no report on compounds of type R'.sub.3 SnOR"' wherein R' is an alkyl or aryl group and R"' is a deoxynucleoside residue or a deoxynucleotide residue as far as we know.
We have investigated on the reaction of an organotin amide compound of general formula (IV): ##STR4## wherein one of R.sup.4 and R.sup.5 is an alkyl or aryl group and the other is a hydrogen atom or an alkyl or aryl group with a deoxynucleoside or deoxynucleotide of general formula (V): ##STR5## wherein R.sup.2, R.sup.3, B and n have the same meanings as defined above and now found that the reaction proceeds according to the reaction equation (1) to give a triorganostannyl derivative of deoxynucleoside or deoxynucleotide of general formula (I) or an amine salt thereof.
Reaction equation (1) ##STR6##
We have further found that the desired triorganostannyl derivative of deoxynucleoside or deoxynucleotide of general formula (I) can also be prepared by replacing the organotin amide compound of general formula (IV) above with a corresponding triorgano(alkoxy)stannane of general formula (VII): EQU R.sup.1.sub.3 SnOR.sup.6 (VII)
wherein R.sup.6 is a secondary or tertiary alkyl group or a 1-substituted cycloalkyl group according to the reaction equation (2). ##STR7##